Is Separation at the Costochondral Junction a Contributing Factor in the Lateral Overgrowth of Costochondral Grafts?

In growing patients, costochondral graft (CCG) is the gold standard for autogenous ramus-condyle unit (RCU) reconstruction. Many factors influence the growth of CCG, such as cartilage length, patient age, diagnosis, surgical technique, functioning of the mandible, use of orthodontic appliances, and hormonal factors. All growing patients below 16 years of age, who underwent reconstruction of RCU with CCG from 2006 to 2021 at our institution, were retrospectively evaluated. Out of 54 patients (36 ankylosis and 18 pathology/others), lateral overgrowth was observed in four cases. In all four cases, the dislodged cartilage cap was encountered intraoperatively and was sutured back over its original position. A literature search revealed an excess height of a cartilaginous cap, pubertal growth spurt, and hormonal influence as possible factors for overgrowth. However, there is no literature on the separation of cartilage cap as a possible factor. This is the first case report to document a causal association between resuturing dislodged cartilage cap resulting in lateral overgrowth.